Emil jacobsen



ST'AI'VES PATENT OFFICE. f

EMIL ajnconsnn, or' nvnNsTcN, IIJJNoIs, nssIcNon-jrcUroMATIC E'Lnc'rnIC COMPANY, or CHICAGO, ILLINOIS, A Conronafrronor ILLINOIS.

AUTOMATIC `'rnrnazrnrolvn srs'rnnr.

T0 @ZZ 'io/1.0m it may concer-n Be it known that I, EMILl JAcosnN, a

citizen of the United States of America, and a resident oi' Evanston, in the county of Cook and Stateof Illinois, have invented certain new and vuseful Improvements inAutomatic TelephoneV Systems, of which the following is a specification.

My invention relates in general to an automatic telephone system and more articularly to an improved automatic switch of the type known'as a selectorswitch, that is, one which Vhas access to a plurality of trunk lines divided into groups and which may be numerically operated to select a dcsired group of trunk lines and will then operate automatically to select an idle trunk linc in that group and extend -a connection thereto.- 4

In the past a selector switchof the standard type has been ,given access to ten trunk lines in a group or level, that is, it might step Aten times automatically vover a level oit ten trunks, and if more trunk lines were desired in a group, then the switch must take more than ten steps, which operation would require too great an expenditure oi time.

The object of my invention is to provide such a selector switch which has a double set of' Wipers and a double bank of contacts associated therewith, together with means for causing the selector, alter both sets of wipers have been raised to a certain level, to test two trunks at each rotary step, so that twenty trunks may be tested insearch of an idle one in the same timel previously taken to test ten trunks, that is, the first trunk in the level associated with the one set-of Wipers is iirst tested. If that is busy the corresponding trunk in theupper bank, associated with the other set of Wipers, `is then tested, and it both are busy the switch. is rotated so that the next pair of trunks may be tested.

I will novv describe the operation of the switch in detail by referrin to theaccompanying drawing in which y have shown ,a calling subscriber A. having a rotary line switch C of a Well known rotary type individual to his line, which is operated to select an idle one of a number of first selectors, one of which is shown at E and which selector E is of the Well known type of Keith Erickson switch ol the side switchless type with sp'eciacatiun of Letter'sratene.' p, PatentediSept; `14, v1920. Application inea July 1, Isls. Seriana 242,749'. Y

the 'addition'oi certain circuits which adapt it to operate in accordance with the features of In invention.

` en the subscriber at substation A moves his receiver a circuit is closed by the switch hook springs for theline relay 2 ol the rotary line switch C in series with the line-circuit. Relay 2 ,oper`at'es in the usual manner to close a circuit fat springs 3 for relay 4 and magnet 6 in series and to at the Same time close a circuit `from magnet 6 directly to the private `wiper 9 through springs l0 'and 11. Therefore if the trunk line upon which the wipers 7, Sand 9 rest is busy, a ground from said wiper 9 willv short circuit the relay 4 before it may operate, and will causo rotary magnet, 6 to 0perate to step the said W1 pers to an idle trunk line. Whensuch idle trunk line is 'reached the relay 4L ene'rgi'zes `in series with the rotary magnet 6, as it is no longer shorted out by ground on Wiper 9. Relay 4, upon energizing, disconnects relay 2 and ground from the line circuit of substation A and connects said line through its front contacts tothe line wipers 7 and 8 which it will be assunieffl noiv rest in cndagelncnt with contacts `connected to the idle selector switch E.

At this time a circuit is closed for the line relay 120i selector E from ground, through Winding 13 .of an induction coil ol normalsprings 14, lower` vvindingfvof` said relay, springs l5 and 16, springs 1T and 'IS wiper 8, to'and through the apparatus ci substation A, and back through Wiper T, springs 19 and 20, springs 21 and 22, and upperivinding of said relay to battery. Relay 12 energizes atthis time, and closes a circuit Vfor relay 23 .from ,ground through springs 21.1 springs 25, springs 26 and. 27, and said relay to battery. Relay 23 operates to prepa-rea circuit at springs 2S and 29 for the vertical 4magnet 30 and relay Bl, and also supplies a holdingr ground to the relay 4 of` line switch C from. ground through springs 32, Wiper 9,.and through 33-38 inclusive to some level oi' the banks from which trunk lines lead to the desired exchange or to switches of any desired type. It is to be understood that the wipers 33, 34 :1nd,35 are the line and private wipers of one set, and have access to one 'banlsof one hundred contacts, while wipers V3G, 37 and 3S are the line and private wipers oi another set and have access to a separate bank of one hundred contacts, und that both sets of wipers are mounted upon the same shait and more' together. Relay 3l which is energized during the operation o't magnet 30 closes a circuit at springs 39 and 40 extending from ground springs 32, springs 4l, oil normal springs 42, springs 40 and 39 and lower winding of relay 43 to battery. Air other branch of this circuit extends from spring 40 through spring 44 and upper winding of relay 43 to battery. Relay 43 is so constructed that it will energize only with both windings energized fully and not with either winding alone. Also neither winding will he fully energized if either of relays 45 or 4G are in series therewith. At the same time a circuit is closed from ground through springs 32, springs 4l, springs 47, winding of relay 46, and upper winding of relay 43 to battery, and another over the same path, through springs 48, relay 45, and lower winding of relay 43 to battery. Relays 45 and 4G are however short circuited at this time by the direct ground circuit through springs 39, 40 and 44, so that only relay 43 energizes. Relay 43, upon energizing, prepares a circuit at springs 49 for the rotary magnet 50, and closes a locking circuit for itself through springs 24 and of relays 45 and As soon as relay 3l l'alls back the circuit of the rotary magnet is completed at springs 5l and 40 so that magnet 50 operates to step the wipers 33, 34, 35 and 36, 37 and 38 onto the first set of con- .acts oi their respective banks. Assume now that the trunks connected to the contacts with which both sets of wipers engage are both idle7 and no ground is therefore con nected to. wipers 35 and 3S. Then as magnet 50 energizes and opens the circuit of re lay 43, said relay' denergizes to open the circuit of magnet 50 in turn. As magnet 50 denergizes it again supplies battery to the windings of relay 43. In this instance however, relays 45 and 46 are no longer short circuited by relay 3l, and relays 45 and 4G both energize over the previously traced circuit in series with the windings of relay 43, which relay 43 however does not energize at this time. Relays 45 and 46 are so arranged that each opens the circuit of the other at either springs 47 or 48 so that only one of said relays will remain energized. Suppose that relay 45 en'ergizes a second earlier than 46, then relay 46 will be cut oil' at springs 47, while relay'45 will energize to disconnect the line relay 12 from the line circuit, connect the line circuit to wipers 23 and 24, disconnect vground from the'linc relay springs at springs 24,'-and Iprepare :.#loeking circuit :tor itself at springs 52 and 53 extending to wiper `35 which is supplied with a holding ground from the switch ahead in the usual manner as soon as the line relay thereofenergizcs. It will be seen therefore that il both of the iist pair of trunk lines tested in a level are idle, the switch will cut through to one or the other oi said lines de pending upon which relay 45 or 46 energizes lirst.

Now if the trunk line which the wipers 36, 3T .and 38 test is busy the operation will bc the same as above except that the ground on wiper 3S will maintain the relay 46 short circuited, so that it cannot energize, and relay 45 will cut through. Suppose the trunk line with which the wipers 33, 34 and 35 connect is busy, then there will be :1 ground present at wiper 35 which will short circuit the winding of relay 45 from said wiper 35, springs 52 and 54, and lower winding of relay 43 to battery. ln this case relay 45 cannot energize, but relay 46 being no longer shorted out, energizes to switch the line circuit to the wipers 36 and'r', disconnect the line relay 12 and ground at springs 25, and also closes a locking circuit for itself extending through springs 55 and 56 and to the private wiper 38, which is also supplied with a holding ground from the switch ahead.

New let us assume that both trunk lines 'tested at this time are busy, then there will he a guarding ground potential ou the con iat-ts tested hy hoth the wipers 35 and 38. ln this rase both oi' the relays 45 and 4G will he short circuited hy this ground and rel-.1y 43 will hare a direct circuit to ground through both its windings and4 the said pri rate wipers. Relay 4?! will therefore encrgize to again close a circuit for the rotary magnet at springs 49 so that the wipers 553-38 inclusive, will bc moved one step onto the next pair of contacts leading -to thenext pair of trunk lines. The same cycle of operations are now again carried on, that is, it either ol these trunks are idle the line circuit will be switched to that trunk line, while if both are busy the switch will rotate until an idle trunk or pair of trunks is located.

ln the drawingl l have shown the lower winding of thc line relay l2 connected to ground through the secondary of an induction coil 13. The secondary oi this coil is connected from ground through condenser 57, and resistance 58 to battery. The interrupter relay 59 is arranged so that itin terniittently supplies ground to the junction of the resistance 58 and condenser 57 so that this condenser' is charged and dis` ill?) ceases, that is, until one ofthe relays 45 and 46 energizes to disconnect the line relay 1Q from the line circuit. This will of. course inform him that anidle trunk line= has been seizedY by his irst Aselector and he may proceed With'the call.

Suppose that the tvventy'trunks in ajlevel are all busy so that the switch operates to the last trunk and then takes another step and the ott normal springs al., 14 and 60.

are operated bythe shaft, then" lthebusy machine M will be connected` in series with the line relay 12 and the calling line through springsGO to .notify the calling, man that all the trunks are busy, the springs il will be' opened to Aprevent the energization of relays 45 or 46, and springs 14 will be opened to disconnect the trunk tone apparatus from the line relay.

It will be seen therefore that I have provided a very efficient type of automatic se,- lector switch which will test 200 trunks in the same time now taken to test 100 trunks, and without the switch being required to take more than ten steps.l

Iilavingfully described and ascertained the features of: my invention, what I consider to be new and desire to have protected by Letters Patent will bepointed out in the appended claims.

What I claim as my invention is:

1. In a telephone system, a line, an automatic switch Stor said Vline having' a plu rality ot sets ot wipers, trunk lines accessible to each set of wipers, means for making :my of said trunk lines busy, means for causing said switch to test apair of said trunk lines simultaneously, and if one o f the tested trunk lines is busy tor extending a connection from said line over the idle trunk.

2. In a telephone system, a line, an automatic switch "for, said line having,r a plurality of sets of Wipers, normally idle trunk lines accessibleto each set of Wipers, means for making any of said trunk lines busy, means for causing said switch to test a pair of said trunk lines simultaneously, and if both ot the tested trunks are busy for causing thc switch to test another pair vo1". said trunk lines.

3. In a telephone system, a' line, an auto-v -inatic switch for said line having a plurality of sets of wipers, trunk lines accessible to each set of Wipers, means for making any of said trunk lines busy, means` for causing said switch to test a pair of said trunk lines simultaneously, and if both of the tested trunks are busy for causing the sniitch to test another-pair of rsaid trunk lines, and 1f one ofthe said last mentioned trunks are `idle for extendin a connection from the line over theidle trunk.`

4L. In a telephone system, a line, an automatic switch for said line having aplurality of sets4 of wipers, trunk lines accessibleto cach set oWiperS, means for making any ci the saidtrunk lines busy, means for causing'said switch to test a plurality of trunk lines simultaneously one for cach set oi wipers, and if any of said trunk lines are idle, for extending aconnection trom said line via said'iviper tothe idle one of said trunk lines. f

Tn a telephone system, a line, un automatic switch for the `line having a plurality ot' sets ol" Wipers, trunk lines aczessible to said Wipers, meansfo'r making any ot said 'trunk lines busy, means for causingsaid sivitchto test a plurality of said trunk lines simultaneously through the medium of said Wipers, said meanscomprising a test relay common to said sets of Wipers, for continuing the operation ot the switch when all the tested trunks are busy,'and a switching relay for eachy set of Wiperskfor extending a connection over its associated set oi wipers when the trunk line tested thereby is idle.

6. In a telephone system, a line, an automatic switch for said liuc for extending, con nections therefrom having a plurality ot wiper sets, groups of trunk lilies ac-rlessible to said` wipers, meansk for making any oi' said truuk lines busy, va-line relay tor said automatic switch controlled over said liuc by impulses corresponding to a digit oi" a called number to cause said switch to brin,f Ir

kcach Wiper set opposite a desired group of trunk lines, and automatic mea-ns for then causing said switch to test a plurality of said trunk lines simultaneously.

7. In a telephone system, a line, an automatic switch ,for said line for cntcnding connections therefrom having aplurality of Wiper sets, groups of trunk lines accessible to said rivipers, means for making any ofsnid trunk lines busy, a line relay for said automatic switch controlled over, said line by impulses` corresponding toa digit of a called number to cause said switch to bring?. each wiper set opposite a desired ,group ot trunk lines, and automatic menus tor then causing; said switch to test u. plurality of said trunklines sinnlltnneously, and it any of the trunk lilies are idle {or causing the switch to'extend la connection from the line over one of the wiper sets to an idle trunk.

8. Ina telephone system, a line, an automatic switch for said line for entendi,up;v connections therefrom having a plurality of Wiper sets, groups of trunk lines accessible to said Wipers, means for making any of said trunk lines busy, a line Irelay for said auto- 

